Bass leaves after amp warms up?

I disagree with hearing perception changes
Simply put the bass when working has punch,heft,depth & moves air while creating excitment & emotion.
After about an hour the bass notes are still there but the kick of the bass drum no longer has the correct punch,the bass does not move air,the bass notes are no longer rounded but flat,etc.

The bass is similar to a Tuba where the notes are full sounding & you can "sing" along with the bass line if desired.This is the foundation of the music that is receding into the background.
I personality think there is something wrong with my electric.I'm having an Electrician come to tighten all the connections as I think something is causing a misfire.

FWIW, I'd just like to emphasize that the impedance curve I linked to earlier shows that the speaker's impedance is in the vicinity of 2.7 ohms at several frequencies in the deep bass and the mid-range, and is less than 4 ohms throughout most of those regions.

Also, I would not attach much significance to amplifier current capability specs, as they usually do not indicate how long the specified current can be sustained for, and my impression is that in many cases that amount of time may be measured in milliseconds.

Regards,
-- Al

Almark what is the conclusion to be drawn from your post?
My MF amp should be adequate @ 200wpc or no

My MF amp should be adequate @ 200wpc or no

My strong suspicion, consistent with points that were made earlier by Foster_9, Mapman, and others, is "no." As I previously indicated, the three amplifiers you have tried either do not have a 4 ohm rating, or have a 4 ohm rating that is not particularly good relative to their 8 ohm rating. That would certainly cast doubt on their ability to handle 2.7 to 4 ohm impedances, which occur in parts of the frequency range that typically require lots of energy.

Regards,
-- Al